As a conventional detection device, for example, there is the one disclosed in Patent Literature 1. The pressure detection device according to Patent Literature 1 is provided with a lower case having a pressure introducing section which introduces a pressure of a fluid; a pressure sensor (a semiconductor type pressure sensor) which is arranged on the pressure introducing section via a base plate; a circuit board which is electrically connected by the pressure sensor and a wire; an upper case which is arranged by thermally caulking the upper case to the lower case, and which houses the base plate, the pressure sensor, and the circuit board or the like, and forms a connector section, wherein an electric power conducting structure is constructed in order of the circuit board, a first lead terminal, a first lead pin at which a penetration capacitor for absorbing an external noise is arranged, and an electrode lead which is exposed from the connector section.